Inspection Procedure 2: Engine Overheating: Diagnosis

WARNING: This page is about a different car, the 2008 Mitsubishi Lancer. However, it is still accessible from the selected car via links, so may be relevant.

STEP 1. Remove the radiator cap and check for coolant contamination.
Q: Is the coolant contaminated with rust and oil?

YES : Replace the coolant (Refer to ENGINE COOLANT CHANGE ). Then go to Step 5.

NO : There is no action to be taken. Go to Step 2.
STEP 2. Check the radiator cap valve opening pressure.

Fig 1: Checking Radiator Cap Valve
Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.

NOTE: Be sure that the cap is clean before testing. Rust or other foreign material on the cap seal will cause an improper reading.
1. Use a cap adapter to attach the cap to the tester.
2. Increase the pressure until the gauge indicator stops moving.
  Minimum limit: 83 kPa (12 psi)
  
  Standard value: 93 - 123 kPa (14 - 18 psi)
Q: Does the reading remain at or above the minimum limit?

YES : Go to Step 3.

NO : Replace the radiator cap. Then go to Step 5.
STEP 3. Check thermostat operation.
Refer to INSPECTION .

Q: Does the thermostat operate correctly?

YES : Go to Step 4.

NO : Replace the thermostat (Refer to REMOVAL AND INSTALLATION ). Then go to Step 5.
STEP 4. Check the drive belt for slippage or damage.
Refer to DRIVE BELTS (CHECK CONDITION) .

Q: Is the drive belt loose or damaged?

YES : Adjust or replace the drive belt. Then go to Step 5.

NO : There is no action to be taken.
STEP 5. Retest the system.
Check the engine coolant temperature.

Q: Is the engine coolant temperature abnormally high?

YES : Return to Step 2.

NO : The procedure is complete.